Helixate FS Dosage

Generic name: ANTIHEMOPHILIC FACTOR, HUMAN RECOMBINANT 250[iU] in 2.5mL;
Dosage form: injection
Drug class: Miscellaneous coagulation modifiers

Medically reviewed by Drugs.com. Last updated on May 22, 2023.

For intravenous use after reconstitution only.

Dose

Dosage and duration of treatment depend on the severity of the factor VIII deficiency, the location and extent of bleeding, and the patient's clinical condition.1 Careful control of replacement therapy is especially important in cases of major surgery or life-threatening bleeding episodes.

Each vial of Helixate FS has the recombinant factor VIII (rFVIII) potency in international units (IU, unit) stated on the label. One IU (unit), as defined by the World Health Organization standard for blood coagulation factor VIII, human, is approximately equal to the level of factor VIII activity found in 1 mL of fresh pooled human plasma.

The expected in vivo peak increase in factor VIII level expressed as IU/dL (or % normal) can be estimated using the following formulas:

Dosage (units) = body weight (kg) × desired factor VIII rise (IU/dL or % of normal) × 0.5 (IU/kg per IU/dL)

IU/dL (or % normal) = Total Dose (IU)/body weight (kg) × 2 [IU/dL]/[IU/kg]

Titrate dose to the patient's clinical response. Patients may vary in their pharmacokinetic (e.g., half-life, in vivo recovery) and clinical responses to Helixate FS.2,3,4 Although the dose can be estimated by the calculations above, it is highly recommended that appropriate laboratory tests, including serial factor VIII activity assays, are performed [see Warnings and Precautions (5.3) and Clinical Pharmacology (12.3)].

On-Demand Treatment and Control of Bleeding Episodes

A guide for dosing Helixate FS for on-demand treatment and control of bleeding episodes is provided in Table 1. The goal of treatment is to maintain a plasma factor VIII activity level at or above the plasma levels (in % of normal or in IU/dL) outlined in Table 1.

Table 1 Dosing for On-Demand Treatment and Control of Bleeding Episodes
Type of Bleeding Episodes	Factor VIII Level Required (IU/dL or % of normal)	Dose (IU/kg)	Frequency of Doses (hours)	Duration of Therapy (days)
Minor Early hemarthrosis, minor muscle or oral bleeds.	20 – 40	10 – 20	Repeat dose if there is evidence of further bleeding.	Until bleeding is resolved
Moderate Bleeding into muscles, bleeding into the oral cavity, definite hemarthroses, and known trauma.	30 – 60	15 – 30	12 – 24	Until bleeding is resolved
Major Gastrointestinal bleeding. Intracranial, intra-abdominal or intrathoracic bleeding, central nervous system bleeding, bleeding in the retropharyngeal or retroperitoneal spaces, or iliopsoas sheath. Fractures. Head trauma.	80 – 100	Initial: 40 – 50 Repeat: 20 – 25	8 – 12	Until bleeding is resolved

Perioperative Management of Bleeding

A guide for dosing Helixate FS during surgery (perioperative management of bleeding) is provided in Table 2. The goal of treatment is to maintain a plasma factor VIII activity level at or above the plasma level (in % of normal or in IU/dL) outlined in Table 2.

Table 2 Dosing for Perioperative Management of Bleeding
Type of Surgery	Factor VIII Level Required (IU/dL or % of normal)	Dose (IU/kg)	Frequency of Doses (hours)	Duration of Therapy (days)
Minor Including tooth extraction	30 – 60	15 – 30	12 – 24	Until bleeding is resolved.
Major Examples include tonsillectomy, inguinal herniotomy, synovectomy, total knee replacement, craniotomy, osteosynthesis, trauma.	100	50 Pre-operatively to achieve 100% activity.	6 – 12 to keep FVIII activity in desired range	Until healing is complete.

Routine Prophylaxis in Adults

The recommended dose for routine prophylaxis is 25 units per kg of body weight three times per week.

Routine Prophylaxis in Children

The recommended dose for routine prophylaxis is 25 IU/kg of body weight every other day.5

Preparation and Reconstitution

Helixate FS is administered by intravenous injection after reconstitution. Patients should follow the specific reconstitution and administration procedures provided by their physicians.

Reconstitute and administer Helixate FS with the components provided with each package. If any component of the package is opened or damaged, do not use this component.

Product reconstitution, administration, and handling of the administration set and needles must be done with caution because percutaneous puncture with a needle contaminated with blood can transmit infectious viruses, including HIV (AIDS) and hepatitis. Place needles in a sharps container after single use. Discard all equipment, including any reconstituted Helixate FS product, in an appropriate container. Obtain immediate medical attention if injury occurs.

For any questions about the handling, reconstitution and administration of Helixate FS, contact CSL Behring Medical Affairs at 1-800-504-5434.

For instructions, patients should follow the recommendations in the FDA-Approved Patient Labeling.

The procedures below are provided as general guidelines for the reconstitution of Helixate FS.

•: Work on a clean flat surface and wash hands thoroughly using soap and warm water before performing the procedures.
•: Reconstitute the product with the components provided with each package. If any component of the package is opened or damaged, do not use this component.
•: Filter the reconstituted product prior to administration to remove potential particulate matter in the solution. Filtering can be achieved by using the Mix2Vial® vial adapter.

Vacuum Transfer and Reconstitution

1.	Prepare the product under aseptic conditions.
2.	Warm the unopened diluent and the concentrate to a temperature not to exceed 37°C or 99°F.
3.	Place the product vial, diluent vial and Mix2Vial on a flat surface.
4.	Ensure product and diluent vial flip caps are removed and the stoppers are treated with an aseptic solution and allowed to dry prior to opening the Mix2Vial package.
5.	Open the Mix2Vial package by peeling away the lid (Fig. 1).
	Leave the Mix2Vial in the clear package. Place the diluent vial on an even surface and hold the vial tight. Grip the Mix2Vial together with the package and snap the blue end onto the diluent stopper (Fig. 2).
6.	Carefully remove the clear package from the Mix2Vial set. Make sure that you only pull up the package and not the Mix2Vial set (Fig. 3).
7.	With the product vial firmly on a surface, invert the diluent vial with the set attached and snap the transparent adapter onto the product vial stopper (Fig. 4). The diluent will automatically transfer into the product vial.
8.	With the diluent and product vial still attached, gently swirl the product vial to ensure the powder is fully dissolved (Fig. 5). Do not shake vial.
9.	With one hand grasp the product-side of the Mix2Vial set and with the other hand grasp the blue diluent-side of the Mix2Vial set and unscrew the set into two pieces (Fig. 6)
10.	Draw air into an empty, sterile syringe. While the product vial is upright, screw the syringe to the Mix2Vial set. Inject air into the product vial. While keeping the syringe plunger pressed, invert the system upside down and draw the concentrate into the syringe by pulling the plunger back slowly (Fig. 7).
11.	Now that the concentrate has been transferred into the syringe, firmly grasp the barrel of the syringe (keeping the syringe plunger facing down) and unscrew the syringe from the Mix2Vial set (Fig. 8). Attach the syringe to an administration set made with microbore tubing. Use of other administration sets without microbore tubing may result in a larger retention of the solution within the administration set.
12	If the same patient is to receive more than one bottle, the contents of two bottles may be drawn into the same syringe through a separate unused Mix2Vial set before attaching the vein needle.

Administration

For intravenous use after reconstitution only.

•: Inspect Helixate FS visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Turbid or discolored solution should be discarded.
•: Store the reconstituted Helixate FS at room temperature prior to administration, but administer it within 3 hours.
•: Administer Helixate FS over a period of 1 to 15 minutes. Adapt the rate of administration to the response of each individual patient. Determine the pulse rate before and during administration of Helixate FS. If there is a significant increase in pulse rate, reduce the rate of administration or temporarily halt the infusion allowing the symptoms to disappear promptly.